I'm curious to know the cruise speeds of different aircraft. Really I just want to know major jetliners (Boeing, Airbus). I know in the C-5 we cruise at ~.77 Mach. What is the fastest jetliner cruise speed and what is the slowest?

"But this airplane has 4 engines, it's an entirely different kind of flying! Altogether"

The limitation on 737 classics (i.e. -300, -400, -500) is .82. On the odd occasions when I've had to consult the FMC, i.e. considering real time weight, C of G, speed and density alt., I don't recall ever seeing more than .78 allowed.

Increasingly I fly slower if I can get away with it for fuel reasons, and consequently often find myself at .71.

We have a nice high MMO on the 727 at 0.90M. The fastest I have done is 0.87M but the fastest we are ever planned for is 0.85M. Normally we are at 0.79-0.80M for fuel economy. The airplane doesn't like anything slower although occasionally we see 0.76M and even though it's not a big difference, it feels like we are crawling sometimes.

Early Learjets, although they look fast, are only good up to about 0.78M, I wouldn't trust that thing over that due to flutter and the weak tail so we did 0.76M for cruise. Falcon 20's can do 0.85M-0.88M but typically we we cruising them at 0.74M when down low.

Quoting c5load (Reply 3):One of my friends in the Air Force claims that the KC-10 Extender cruises about .85, did the DC-10 normally do this?

Though most airlines cruise DC-10s around M.82 (if I recall correctly), M.85 would be perfectly reasonable for the airframe if fuel burn wasn't a prime consideration.

The 747 varies a lot depending on weight, temperature, model, and airline procedures. 747-400s seem to be happiest between M.82 and M.86, with Boeing listing M.85 as a typical cruise speed. The VC-25A often cruises in excess of M.88.

Not sure about commercial 737s, but our BBJs typically do between M.80 and M.82, though to get max range we need to slow them down a bit. Our 767 typically runs at M.80.

The speed champion of civil aircraft, at least for a while longer, is the Cessna Citation X. Most operators plan between M.85 and M.90. Under certain conditions, we've run them as fast as M.92.